Welcome to LQ.
Boy! That's a mouthful. I think the answers may be beyond a simple forum post.
I'm going to suggest you take a look at
Samba by Example. I think that will help you more than a bunch of disjointed forum posts. Don't be dismayed by the fact that it refers to Samba v. 3; the part of Samba you need didn't change between v. 3 and v. 4.
Samba by Example takes you through scenarios for setting up Samba, ranging from very simple to very complex, including example configuration files. (You can
get a PDF here. I still have my printed-out copy on my bookshelf.)
When I set up my first file server with Samba, I had all the same questions you have and I found what I needed by about page 20.
You also need to look into how to
configure your /etc/fstab to mount the partitions properly (that is, the way you want them to be mounted).
As for setting up Samba, there are three steps:
- Create the directories to be shared and configure them as "shared" in the directory permissions. This one is simple, but takes place independently of the samba configuration and is often overlooked by first-timers. Like I was.
- Create your /etc/samba/samba.conf file, then start samba. This is more complicated.
- Troubleshoot anything that's not working.
As an aside, the more specific information you provide, the easier it will be for others to help you. You might want
to take a look at this; it will help you help us help you.
Edit:
If I remember correctly, Ubuntu by default includes samba-client, but does not include samba-server. You may need to install samba-server from the repos.